Exhibit 4.3


 


AMENDMENT
AGREEMENT


 


This
AMENDMENT AGREEMENT (the “Amendment”), dated as of June 30, 2018, is made by and between Ener-Core,
Inc., a Delaware corporation, with headquarters located at 8965 Research Drive, Suite 100, Irvine, California 92618 (the “Company”),
and the investor listed on the signature page attached hereto (the “Holder”). Capitalized terms used herein
and not otherwise defined herein shall have the respective meanings set forth in the Bridge SPA (as defined below), as applicable.


 


RECITALS


 


A. Reference
is made to that certain Securities Purchase Agreement dated as of September 19, 2017, by and among the Company, the Holder and
the other investors listed on the signature pages attached thereto and party to a joinder agreement thereto (as amended and/or
restated from time to time, the “Bridge SPA”); and the Senior Secured Notes issued to the Holder pursuant thereto
(as amended from time to time prior to the date hereof, the “Bridge Notes”);


 


B. The
Company and the Holder desire to amend each of the Bridge Notes as set forth herein; and


 


C. In
compliance with Section 15 of the Bridge Notes, this Amendment shall only be effective upon the execution and delivery of this
Amendment and agreements in form and substance identical to this Amendment (other than with respect to the identity of the Holder
and any provision regarding the reimbursement of legal fees) (together with this Amendment, the “Amendments”)
by the Required Holders (as defined in the Bridge Notes).


 


AGREEMENT


 


NOW
THEREFORE, in consideration of the foregoing mutual premises and the covenants and agreements hereinafter set forth, and for
other good and valuable consideration, the receipt, and legal adequacy of which is hereby acknowledged, the parties hereto, intending
to be legally bound, hereby agree as follows:


 


ARTICLE
I


NOTES


 


1. Optional
Redemption at the Holder’s Election. The first sentence of Section 7 of the Bridge Notes is hereby amended and restated
as follows:


 


“At
any time from and after January 1, 2019 and provided that the Company shall not have received either (i) initial deposits for
at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial
payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on December
31, 2018 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that
the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note
then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the
Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall
state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur,
which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder
Optional Redemption Date”).”


  



     


     


    

 


Notwithstanding
the foregoing, effective upon the issuance by the Company of convertible senior secured promissory notes for aggregate gross proceeds
of at least $2.0 million pursuant to that certain Securities Purchase Agreement, dated as of June 5, 2018, by and among the Company,
the investors set forth on the Schedule of Buyers thereto and the investors, if any, party to a joinder agreement with respect
thereto, as the same may be amended or otherwise modified from time to time pursuant to the terms thereof:


 


		a.	Section
                                         7. Section 7 of the Bridge Notes is hereby amended and restated as follows:



 


“[Reserved].”


 


		b.	Section
                                         11(a). The third sentence of Section 11(a) of the Bridge Notes is hereby deleted.



 


		c.	Section
                                         30(ee). The phrase “Holder Optional Redemption Dates” is hereby deleted
                                         from Section 30(ee) of the Bridge Notes.



 


		d.	Section
                                         30(ff). The phrase “Holder Optional Redemption Notices” is hereby deleted
                                         from Section 30(ff) of the Bridge Notes.



 


		e.	Section
                                         30(gg). The phrase “Holder Optional Redemption Prices” is hereby deleted
                                         from Section 30(gg) of the Bridge Notes.



 


ARTICLE
II

MISCELLANEOUS


  


1. Effect
of this Amendment. This Amendment shall form a part of the Bridge Notes for all purposes, and each holder of Bridge Notes
shall be bound hereby. This Amendment shall only be deemed to be in full force and effect from and after both the execution of
this Amendment by the parties hereto and the execution of Amendments substantially identical to this Amendment by the Company
and the Required Holders (as defined in the Bridge Notes). From and after such effectiveness, any reference to the Bridge Notes
shall be deemed to be a reference to the Bridge Notes, as amended hereby. Except as specifically amended as set forth herein,
each term and condition of the Bridge Notes shall continue in full force and effect.


  


2. Entire
Agreement. This Amendment, together with the Bridge SPA and Bridge Notes, as amended to date, contains the entire agreement
of the parties with respect to the matters contemplated hereby and thereby, and supersedes any prior or contemporaneous written
or oral agreements between them concerning the subject matter of this Amendment.


  


3. Governing
Law. This Amendment shall be governed by the internal law of the State of New York.


  


4. Counterparts.
This Amendment may be executed in any number of counterparts and by different parties hereto in separate counterparts, each of
which when so executed and delivered shall be deemed an original, but all such counterparts together shall constitute but one
and the same instrument; signature pages may be detached from multiple separate counterparts and attached to a single counterpart
so that all signature pages are physically attached to the same document. This Amendment may be executed by fax or electronic
mail, in PDF format, and no party hereto may contest this Amendment’s validity solely because a signature was faxed or otherwise
sent electronically.


  


[Signature
Page Follows]


  



    	 	2	 



     


    

 


IN
WITNESS WHEREOF, the Holder and the Company have caused their respective signature pages to this Amendment to be duly executed
as of the date first written above.


  


	 	COMPANY:
	 	 
	 	ENER-CORE,
    INC.
	 	 	
	 	By:	
	 	 	Name: 	Domonic
    J. Carney
	 	 	Title:  	Chief
    Financial Officer


 


Signature
Page to Amendment Agreement—June 2018



     


     


    

 


IN
WITNESS WHEREOF, the Holder and the Company have caused their respective signature pages to this Amendment to be duly executed
as of the date first written above.


  


	 	HOLDER:
	 	 
	 	By: 
	 	 
	 	By:	 
	 	 	Name:
	 	 	Title:




  


Signature
Page to Amendment Agreement—June 2018